Posted
by
samzenpus
on Monday July 29, 2013 @09:30AM
from the throwing-it-out-there dept.

cylonlover writes "People have been shooting things into space since the 1940s, but in every case this has involved using rockets. This works, but it's incredibly expensive with the cheapest launch costs hovering around $2,000 per pound. This is in part because almost every bit of the rocket is either destroyed or rendered unusable once it has put the payload into orbit. Reusable launch vehicles like the SpaceX Grasshopper offer one way to bring costs down, but another approach is to dump the rockets altogether and hurl payloads into orbit. That's what HyperV Technologies Corp. of Chantilly, Virginia is hoping to achieve with a 'mechanical hypervelocity mass accelerator' called the slingatron."

A kickstarter for a version that'll launch 1lb loads up to a small portion of the speed of sound. You're not getting anything in to orbit on the back of this, just helping this guy make a marginally more convincing case to bigger funding agencies. Although if the physics and engineering made sense, I'm not sure why a marginally larger prototype than the ones they already have is needed.

It’s questionable whether any rocket system could survive such stresses and there’s certainly no chance of a slingatron being used on a manned mission because it would turn an astronaut into astronaut pudding. Only the most solid state and hardened of satellites built along the lines of an electronic artillery shell fuse would have a chance of survival. The developers say that a larger slingatron would reduce the forces, but even with a reduction by a factor of 10,000, it would still be restricted to very robust cargoes. This makes it mainly attractive for raw materials, such as radiation shielding, fuel, water, and other raw materials.

Lets assume orbital velocity is enough and there are no loses to the atmosphere. So we need about 7500m/s. Now we can see what acceleration we need for a track "several ks long". a=v*v/(2s) =14062m/s^2. Or 1433 g's. Best not to be a fragile meat bag. Lets assume we can make a 20km track. Well that is 10x longer so we get one tenth the acceleration. Or only 140g's. 200km seems a better 14g's. Of course this 14 g's last for 53 secs. One hell of a ride.

Real numbers would be much worse. For a muzzle V of 10km/s they are 77% worse.

The slingshot is in fact a far less realistic approach, we could build a mag train with these specs if we were so inclined to sink the billions it would cost to do so. But the slingshot has very large forces between the "track" and the projectile while still requiring a massive track that all moves!

Personally if we are going to dream then a launch loop is my preferred "rockets suck" alternative.

By the way Rockets don't suck. They do what they do well. Far better than anything else at this point. There is no reason they have to be as expensive as they currently are.